The flame-haired artist Jeanne-Claude – or Mrs Christo, as she sometimes called herself – worked with her husband to mummify the Pont Neuf, to envelop a string of Miami islands in flamingo-pink nylon, to bind the German Reichstag building in aluminium fabric and to erect 7,503 billowing, saffron "gates" in Central Park, New York. She has died aged 74, from complications of a brain aneurism suffered after a fall.

Jeanne-Claude Denat de Guillebon was born in Casablanca, Morocco, where her father, a French general, was stationed at the time. She was born on exactly the same day as her husband and collaborator, Christo Javacheff. "Both of us at the same hour," Jeanne-Claude liked to say, "but, thank God, two different mothers." She often acted as spokesperson for the pair, explaining that as "twins", they had an almost symbiotic relationship and spoke in one voice (usually hers). "Sometimes we would both have the same idea at the same time," she marvelled, "You know how people who live with a dog start looking like their dogs?"

She was much more than simply his muse or manager. Until 1994, all their artworks bore only Christo's name, apparently because they thought it would be easier for one artist to become established, but since then the pair have shared the credit. It was entirely her idea, Christo said after the fact, to create Surrounded Islands (1980-83), which used 6m sq ft of pink fabric to outline an archipelago in Miami as if with a highlighter pen ("a giant Pepto-Bismol spill", according to one critic). Christo retroactively corrected the record and now they are acknowledged as joint authors of every outdoor installation they plotted from 1961 onwards. That year Christo proposed the wrapping of their first building, the École Militaire in Paris (perhaps an Oedipal proposition on Jeanne-Claude's part).

She met Christo in 1958, soon after he moved to Paris from his native Bulgaria, where his father owned a textile factory. Influenced by Man Ray, who in 1920 wrapped a sewing-machine in a blanket, bound it with string and photographed it to illustrate the surrealist's famous definition of beauty – "the chance encounter of a sewing-machine and an umbrella on a dissecting table" – Christo had begun to parcel objects. In his humble attic studio, he wrapped cans, bottles, shoes, chairs – which he considered his "real" art and autographed with his first name – while paying his way by washing dishes and painting conventional portraits, which he signed with his surname.

Jeanne-Claude's mother was impressed with a Javacheff portrait she spied at her hairdresser's, and invited the struggling migrant to the family chateau to paint one of her. Their debutante daughter remembers seeing the artist at work and remarking: "Mother's brought home another stray." She assumed Christo was gay. "He is so skinny," she said to her mother, "and he's got long thin hands – and he paints."

Christo invited Jeanne-Claude up to his garret to see the sculptural work of which he was more proud. "Christo opened the door and I had a split second to see what was inside and then it was dark," Jeanne-Claude recalled. "In that second, what I had seen was packages from the floor to the ceiling, all piled up on top of each other. And I thought, 'My God, this guy is crazy.'" But, despite first impressions, and to her parents' disappointment, the two fell in love. Jeanne-Claude walked out of a three-week-long marriage to an older man and in 1960 had a child with Christo – Cyril Christo, now a poet. Her parents refused to speak to her for two-and-a-half years. "They loved Christo as a son but not as a son-in-law," she said.

Christo gave Jeanne-Claude a crash course in the history of art – until then she had thought the Louvre, with its "superb wooden parquet" floors, fit only for illegal roller-skating sprees. She, in turn, encouraged him to embrace increasingly bigger things – a car, a tree, a cliff, a bridge, an island, a parliament. The more expensive and ambitious the scheme, the more surreal it seemed and the more publicity it attracted. Their installations were media events. Christo referred to his iconoclastic creations with some pride as "irrational, irresponsible, useless".

The couple emigrated from Paris to New York in 1964. "We immediately loved New York," Jeanne-Claude said. "As we were standing on the prow of the SS France, suddenly there it was in front of us. And Christo took me in his arms and said, 'Do you like it? I love it! I give it to you, it's all yours!'" (He proposed, but never got permission, to wrap several skyscrapers.)

Their relationship lasted 51 years, and they did everything together, Jeanne-Claude said, except three things: "We never fly on the same airplane… I do not draw. Christo is the one who puts on paper our ideas… And I have always deprived him of the joy of working with our accountant." She described their union as passionate and volatile. "We are terribly argumentative and scream and criticise each other non-stop," she admitted. "It is very helpful. It makes us think. Christo is right 75% of the time."

In January 2005 I met the couple in Central Park as they prepared for The Gates to be installed, the only public artwork they managed to realise in their adopted city. They wore his'n'hers white fur hats and identical coats for protection against the snow. Jeanne-Claude had lipstick to match her signature dyed red shock of hair, leg-warmers up to her knees, grey steely eyes and an omnipresent cigarette. She was a forceful presence and did most of the talking. Christo was anxious and impatient, keen to get back to their SoHo studio to continue the "preparatory" sketches that were sold to finance the huge cost of the project ($23m). "We do not accept sponsors," Jeanne-Claude explained, "because we wish to work in total freedom. We want to do what we want, where we want it, how we want it… but not always when we want it."

Jeanne-Claude spearheaded the lengthy campaigns to obtain permits. Her tenacity was legendary and forbidding. The artists spent years in public hearings, courts and even parliamentary sessions (the Bundestag voted on whether or not they should be allowed to wrap the Reichstag building), in their determination to see their concepts realised. "The most difficult part is getting the permits," Jeanne-Claude told me. "It took us 25 years to finally wrap the Reichstag [building]… 10 years to wrap the Pont Neuf… 35 to wrap the trees in Switzerland. We have completed 18 projects, The Gates will be the 19th, but we have failed, F_A_I_L_E_D, 37 projects. They were refused and we have lost interest in them. We do those projects for us, we do not do it for the public." When she died, Jeanne-Claude was working on their plan, conceived in 1992, to cover six miles of the Arkansas river in Colorado with shimmering, translucent fabric.

Their fleeting and dramatic interventions have been immortalised in six films by the documentary maker Albert Maysles. The first of these, Christo's Valley Curtain (1974), about the huge, orange fabric dam they built in Colorado, was nominated for an Oscar. Maysles's stylish films bring the couple's ephemeral artworks vividly back to life and record Jeanne-Claude's dogged attempts at diplomacy and the almost military discipline she brought to their realisation. We follow the exhilarating process of their construction, with all the snags, and enjoy the construction workers' and onlookers' arguments about whether or not they are art.

"Jeanne-Claude and I borrow space and create a gentle disturbance in it for just a few days," Christo has said of their work. "When they appear for a few days, they carry this tremendous freedom of irresponsibility."

Christo and Cyril survive her.

• Jeanne-Claude (Javacheff), artist, born 13 June 1935; died 18 November 2009